1. Field
Apparatuses and methods consistent with exemplary embodiments relate to an energy storage system and a method of storing energy and recovering the stored energy using the system.
2. Description of the Related Art
In the case of power generation systems, such as power generation systems using new renewable energy where amounts of generated power per unit time are irregular, temporary storage of energy is needed to allow for amounts of generated power per unit time to be constant.
In the related art, previously used pumped-storage power plants or compressed air energy storage (CAES) systems are used as facilities for temporary storage of surplus energy.
Pumped-storage hydroelectricity is an energy storage method in which water is pumped from a lower elevation reservoir to a higher elevation reservoir by using surplus power, thereby converting electric energy into potential energy. The pumped-storage hydroelectricity is disadvantageous due to expenses incurred for installation, as huge facilities are required for forming head drop of water.
On the other hand, CAES systems are on a smaller scale than pumped storage power plants but lose energy due to external dispersion of heat generated while compressing air. Also, when generating power while discharging air, a temperature is lowered resulting in reduction in volume of the discharged air and decrease in efficiency of electric power generation.